Alkaline earth metals are denser than alkali metals because metallic bonding is:

Which of the following sulphates is insoluble in water?

Calcium is obtained by which of the following methods?

Calcium salts give which colour when put in a flame?

$A$ metal is burnt in air and the ash on moistening smells of $NH_3$. The metal is

Match the compounds in List-$I$ with their chemical formulas in List-$II$ and select the correct answer using the codes given below:
List-$I$ (Compounds) | List-$II$ (Formulas)
$(A)$ Plaster of Paris | $(i) \, CaSO_4 \cdot 2H_2O$
$(B)$ Epsomite | $(ii) \, CaSO_4 \cdot \frac{1}{2} H_2O$
$(C)$ Kieserite | $(iii) \, MgSO_4 \cdot 7H_2O$
$(D)$ Gypsum | $(iv) \, MgSO_4 \cdot H_2O$